1. Field of the Invention
The present invention relates to a catalyst for the production of xcex1-olefin and also to a method for the production of xcex1-olefin. More particularly, it relates to a catalyst by which xcex1-olefin can be efficiently produced and also to a method for the production of xcex1-olefin by means of oligomerization of ethylene using the said catalyst.
2. Description of the Related Art
In the production of xcex1-olefin by oligomerization of ethylene, a method in which a transition metal complex is used as a main catalytic component while an oxygen-containing organoaluminum compound such as alumoxane or a boron compound such as perfluorotetraphenyl borate is used as a co-catalyst has been known already. However, the necessary amount of such a co-catalyst to the main catalyst is usually several hundred times moles whereby the activity per catalyst is low and the productivity is bad. In addition, the yield of C6, C8 and C10 components which are highly demanded is insufficient.
The present invention has been achieved in view of the above and an object of the present invention is to provide a catalyst which is able to express a high oligomerizing activity to ethylene and also to provide a method for the production of xcex1-olefin by oligomerization of ethylene using the catalyst.
In the present invention, xcex1-olefin (oligomer) stands for a polymer having a molecular weight of 10,000 or less and is different from common high molecular substances having higher molecular weight and expressing the characteristics inherent to the high molecular substances. Accordingly, the property demanded for the catalyst used for the production of xcex1-olefin (oligomer) is different from the property demanded for the catalyst for the production of high molecular substances. Consequently, it is not true that a catalyst for the production of high molecular substances (polyolefins) can always be used for the production of xcex1-olefin as it is.
The present inventors have found that the above-mentioned object can be effectively achieved by the use of a transition metal complex of Groups 4 to 6 of the Periodic Table or a transition metal complex of Groups 8 to 10 of the Periodic Table as a main catalyst and also by the use of clay, clay mineral or ion-exchange layer compound as a co-catalyst whereby the present inventors have accomplished the present invention.
The present invention may be divided into the first feature using a transition metal complex of Groups 4 to 6 of the Periodic Table as a main catalyst and the second feature using a transition metal complex of Groups 8 to 10 of the Periodic Table as a main catalyst. As a result of adoption of the first feature, the above-mentioned object can be achieved and high yield of C6, C8 and C10 components can be achieved as well. As a result of adoption of the second feature, the above-mentioned object can be achieved and production of by-products such as heavy-weight components and wax component can be held to a low level.
Thus, the gist of the present invention is as follows.
The first feature of the present invention relates to:
(1) a catalyst for the production of xcex1-olefin obtained by contacting (a) clay, clay mineral or ion-exchange layer compound with (b-1) a transition metal complex of Groups 4 to 6 of the Periodic Table;
(2) the catalyst for the production of xcex1-olefin according to the above (1), wherein ligand of the transition metal complex which is the component (b-1) has a conjugated five-membered ring;
(3) the catalyst for the production of xcex1-olefin according to the above (1) or (2), wherein the transition metal in the component (b-1) is zirconium;
(4) the catalyst for the production of xcex1-olefin according to any of the above (1) to (3), wherein the clay, the clay mineral or the ion-exchange layer compound which is the component (a) contains an inorganic substance containing phyllosilicate;
(5) the catalyst for the production of xcex1-olefin according to any of the above (1) to (4), wherein the clay, the clay mineral or the ion-exchange layer compound which is the component (a) is montmorillonite;
(6) the catalyst for the production of xcex1-olefin according to any of the above (1) to (5), wherein the clay, the clay mineral or the ion-exchange layer compound which is the component (a) is that which is treated with an organosilane compound; and
(7) a method for the production of xcex1-olefin, characterized in that, ethylene is oligomerized using the catalyst for the production of xcex1-olefin which is mentioned in any of the above (1)-(6).
The second feature of the present invention relates to:
(8) a catalyst for the production of xcex1-olefin obtained by contacting (a) clay, clay mineral or ion-exchange layer compound with (b-2) a transition metal complex of Groups 8 to 10 of the Periodic Table;
(9) the catalyst for the production of xcex1-olefin according to the above (8), wherein ligand of the transition metal complex which is the component (b-2) has a carbon-nitrogen unsaturated bond;
(10) the catalyst for the production of xcex1-olefin according to the above (8) or (9), wherein the clay, the clay mineral or the ion-exchange layer compound which is the component (a) contains an inorganic substance containing phyllosilicate;
(11) the catalyst for the production of xcex1-olefin according to any of the above (8) to (10), wherein the clay, the clay mineral or the ion-exchange layer compound which is the component (a) is montmorillonite; and
(12) a method for the production of xcex1-olefin, characterized in that, ethylene is oligomerized using the catalyst for the production of xcex1-olefin which is mentioned in any of the above (8)-(11).